ALGEBRAIC DERIVATIVE ESTIMATION AND APPLICATIONS IN ADAPTIVE CONTROL OF MAGNETIC LEVITATION SYSTEMS
Matheus Schwalb Moraes1; Paulo Sergio Pereira da Silva1
1 University of São Paulo
doi:10.20906/CPS/COB-2015-1134
Resumo
The algebraic derivative estimation method is used to provide a fast online state estimation in magnetic levitation control. Since magnetic levitation plants are highly nonlinear and unstable, nonlinear adaptive control is used to handle uncertainties on physical parameters. The state estimation is used together with two adaptive control schemes (filtered Least Squares parameter estimation and Lyapunov-based adaptive control law). The proposed approaches aim the improvement of tracking performance, which is the main concern in the early stage of levitation, where a undesired overshoot can stick the magnet with the levitated object. Experimental results were obtained in a laboratory prototype showing the excellent performance of the proposed adaptive control schemes when combined with the algebraic estimator. The two control approaches are compared and some properties of the algebraic estimation method in closed loop with a feedback law are discussed.
Palavras-chave: derivative estimation; adaptive control; nonlinear control; parameter estimation; magnetic levitation